Cell viability assays showed that compared to HCC cells with low expression levels of TBC1D31 accompanied by low EGFR levels/activities (e.g., HepG2 and SMMC‐7721), the TBC1D31‐amplified and/or ‐overexpressed HCC cells accompanied by high EGFR levels/activities (e.g., HCCLM3, Huh7 and Bel‐7402) exhibit a markedly increased resistance to lenvatinib (Figure 7b; Figure S9a, Supporting Information). The gene discussed is EGFR; the disease is hepatocellular carcinoma.